1. Field of the Invention
The invention pertains to a method for the manufacture of a mechanically shielding layer for a magnetic read/write head, and a read/write head in which this method is applied, especially in the technology of integrated magnetic heads.
2. Description of the Prior Art
Integrated magnetic heads are currently produced as reading or writing elements for hard disks. In this use, the magnetic heads float above the surface of the disk. The floating height is a few microns and the heads, when they are being used, never enter into friction against the disk except when the disk is started or stopped.
By contrast, in instruments of the videotape recorder type, the recording medium is a magnetic tape, made either of an oxide or of metal, and the heads are in contact with the tape. This results in a rate of abrasion which, according to present standards for VHS heads, is 20 micrometers for 2000 hours of working, thus setting the lifetime of the videotape recorder.
For thin layer heads, the problem of the interface between the tape and the read/write head is a more crucial one because it relates to dimensions of a few micrometers for active magnetic parts. For the thin layer deposits are about 5 micrometers thick, and the gap is 0.2 micrometer thick while the substrate on which the layers are set are about 500 micrometers thick.
Thus, it is worthwhile to shield the active parts of magnetic heads against premature wearing out.
This is why the invention proposes a method to make a shielding layer on the active surfaces of magnetic heads, the layer obtained being thin enough, and having a uniform thickness so that the quality of the head is not harmed.